Detecting spontaneous symmetry breaking in finite-size spectra of frustrated quantum antiferromagnets

TL;DR

This paper reviews how exact diagonalization and symmetry analysis can detect spontaneous symmetry breaking in frustrated quantum antiferromagnets, with new insights into kagome and star lattice models.

Contribution

It introduces new results on kagome and star lattice Heisenberg antiferromagnets using symmetry analysis of spectra.

Findings

Symmetry analysis reveals signatures of symmetry breaking.

Exact diagonalization provides detailed low-energy spectra.

New results on kagome and star lattice models.

Abstract

Exact diagonalization is a powerful numerical technique to analyze static and dynamical quantities in quantum many-body lattice models. It provides unbiased information concerning quantum numbers, energies and wave-functions of the low-energy eigenstates for almost any kind of microscopic model. The information about energies and quantum numbers is particularly useful to detect possible spontaneous symmetry breaking at T=0. We review some of the advances in the field of frustrated quantum magnets which have been possible thanks to detailed symmetry analysis of exact diagonalizations spectra. New results concerning the kagome and star lattice Heisenberg antiferromagnets are presented.